Default Linux toolchain linker to gold

The BFD linker on most of the Linux box is unable to link Swift objects.
Currently the Swift driver hard-codes forcing the default linker to
gold, but we want to support configuring this, so we need build-script
to force it at the clang level instead.

Cherry-Picks:
  d63152f
  7596d00
  8262552

Author: etcwilde

utils/build-presets.ini

@@ -914,6 +914,9 @@ install-foundation
 install-libdispatch
 reconfigure
 
+llvm-cmake-options=
+  -DCLANG_DEFAULT_LINKER=gold
+
 [preset: buildbot_linux]
 mixin-preset=
     mixin_lightweight_assertions,no-stdlib-asserts
@@ -1066,6 +1069,8 @@ reconfigure
 skip-test-lldb
 test-optimized
 
+llvm-cmake-options=
+  -DCLANG_DEFAULT_LINKER=gold
 
 [preset: buildbot_linux_1404_no_lldb]
 mixin-preset=buildbot_incremental_linux
@@ -1144,6 +1149,8 @@ reconfigure
 # in Linux CI bots
 relocate-xdg-cache-home-under-build-subdir
 
+llvm-cmake-options=
+  -DCLANG_DEFAULT_LINKER=gold
 
 [preset: buildbot_incremental_linux]
 mixin-preset=
@@ -1762,6 +1769,9 @@ skip-test-foundation
 skip-test-libdispatch
 skip-test-xctest
 
+llvm-cmake-options=
+  -DCLANG_DEFAULT_LINKER=gold
+
 # Builds enough of the toolchain to build a swift package on macOS.
 [preset: mixin_swiftpm_package_macos_platform]
 mixin-preset=mixin_swiftpm_macos_platform
@@ -1784,6 +1794,8 @@ mixin-preset=mixin_swiftpm_linux_platform
 skip-test-llbuild
 skip-test-swiftpm
 
+llvm-cmake-options=
+  -DCLANG_DEFAULT_LINKER=gold
 
 #===------------------------------------------------------------------------===#
 # Test swiftPM on macOS builder
@@ -2035,6 +2047,9 @@ skip-test-swift
 skip-test-libdispatch
 skip-test-foundation
 
+llvm-cmake-options=
+  -DCLANG_DEFAULT_LINKER=gold
+
 #===------------------------------------------------------------------------===#
 # Remote Mirror Library
 #===------------------------------------------------------------------------===#
@@ -2814,6 +2829,9 @@ install-libdispatch
 install-xctest
 swift-install-components=autolink-driver;compiler;clang-builtin-headers;stdlib;libexec;swift-remote-mirror;sdk-overlay;license
 
+llvm-cmake-options=
+  -DCLANG_DEFAULT_LINKER=gold
+
 [preset: source_compat_suite_macos_DA]
 mixin-preset=source_compat_suite_macos_base
 debug
@@ -2900,6 +2918,9 @@ skip-test-swift
 skip-build-benchmarks
 skip-test-foundation
 
+llvm-cmake-options=
+  -DCLANG_DEFAULT_LINKER=gold
+
 # Temporarily disable early swift driver builds so that linux images
 # can use the swift release images as a base.
 skip-early-swift-driver